Method for making an article of footwear

ABSTRACT

A method for making a footwear includes the steps of preparing an upper that has a bottom peripheral edge, preparing a thermoplastic skin that has a base wall and a peripheral wall and that confines an inner space, preparing a filler pad, mounting the upper on a last, preheating the thermoplastic skin to a softened state, and thermal molding the softened thermoplastic skin together with an assembly of the filler pad and the upper in such a manner that the filler pad is fittingly received in the inner space and is bonded to the base wall and the peripheral wall.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for making an article of footwear,more particularly to a method for making an article of footwear that hasan outsole including a thermoplastic skin and a filler pad surrounded byand bonded to the thermoplastic skin.

2. Description of the Related Art

A conventional method for making an article of footwear normallyinvolves thermal molding of an assembly of an upper, an insole or amidsole, and an outsole in a mold such that the midsole or the outsoleis softened during the molding operation for bonding to the upper. Theconventional method is disadvantageous in that the time required forsoftening the midsole or the outsole is relatively long by virtue of therelatively large thickness of the midsole or the outsole.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a methodfor making an article of footwear that is capable of overcoming theaforementioned drawback.

According to the present invention, there is provided a method formaking an article of footwear. The method comprises the steps of:preparing an upper that has a bottom peripheral edge; preparing athermoplastic skin that has a base wall and a peripheral wall whichextends from a periphery of the base wall in a transverse directionrelative to the base wall and which confines an inner space therein, theperipheral wall having a shape that conforms to that of the bottomperipheral edge of the upper; preparing a filler pad that has a shapeconforming to that of the base wall; mounting the upper on a last;preheating the thermoplastic skin to a softened state; and thermalmolding the softened thermoplastic skin together with an assembly of thefiller pad and the upper in a mold in such a manner that the peripheralwall of the thermoplastic skin is patterned and is bonded to the bottomperipheral edge of the upper and that the filler pad is fittinglyreceived in the inner space and is bonded to the base wall and theperipheral wall of the thermoplastic skin.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings which illustrate embodiments of the invention,

FIG. 1 is a block diagram illustrating consecutive steps of the firstpreferred embodiment of a method according to this invention for makingan article of footwear;

FIG. 2 is a sectional view to illustrate how a filler pad is enclosed ina space between an upper and a skin of the article of footwear accordingto the first preferred embodiment of this invention;

FIG. 3 is a sectional view showing the filler pad of FIG. 2, which ismade from two different materials;

FIG. 4 is a sectional view showing a wear-resistant pad, which isattached to a bottom of the skin of FIG. 2;

FIG. 5 is a block diagram illustrating consecutive steps of the secondpreferred embodiment of the method according to this invention;

FIG. 6 is a sectional view to illustrate how the skin is connected tothe upper of the article of footwear according to the second preferredembodiment of this invention;

FIG. 7 is a sectional side view showing an article of footwear, which ismodified from that of FIG. 6, and which includes reinforcing ribs formedon the skin;

FIG. 8 is a sectional bottom view showing the reinforcing ribs of FIG.7; and

FIG. 9 is a sectional view to illustrate how the skin is connected tothe upper of the article of footwear according to the third preferredembodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For the sake of brevity, like elements are denoted by the same referencenumerals throughout the disclosure.

FIG. 1 is a block diagram showing consecutive steps of the firstpreferred embodiment of a method of this invention for making an articleof footwear.

With reference to FIG. 2, the method includes the steps of: preparing anupper 10 that has a bottom peripheral edge 12 confining a bottom opening14; applying an adhesive to a peripheral wall of the upper 10; bindingan insole 13 to the bottom peripheral edge 12 of the upper 10; preparinga thermoplastic skin 22 that has a base wall 221 and a peripheral wall222 which extends from a periphery of the base wall 221 in a transversedirection relative to the base wall 221 and which confines an innerspace 223 therein, the peripheral wall 222 having a shape that conformsto that of the bottom peripheral edge 12 of the upper 10; preparing afiller pad 21 that has a shape conforming to that of the base wall 221;mounting the upper 10 on a last 30; attaching a tape 40 on theperipheral wall of the upper 10 above the bottom peripheral edge 12 ofthe upper 10 for preventing formation of flash on the peripheral wall ofthe upper 10; preheating the thermoplastic skin 22 to a softened state;thermal molding the softened thermoplastic skin 22 together with anassembly of the filler pad 21, the insole 13, the upper 10 and the tape40 in a mold 100 in such a manner that the peripheral wall 222 of thethermoplastic skin 22 is patterned and is bonded to the bottomperipheral edge 12 of the upper 10 and that the filler pad 21 isfittingly received in the inner space 223 and is bonded to the base wall221 and the peripheral wall 222 of the thermoplastic skin 22 so as tocooperate with the thermoplastic skin 22 to form an outsole 20 of thearticle of footwear; cooling the mold 100; removing the resultantarticle of footwear from the mold 100; trimming the article of footwear;and removing the tape 40 from the article of footwear. The preheatingoperation of the thermoplastic skin 22 can be carried out in the mold100 so as to reduce the manufacturing time.

The thermoplastic skin 22 is preferably made from ethylene vinylacetatecopolymer or thermoplastic urethane. The filler pad 21 can be made fromplastic waste, such as polyurethane, ethylene vinylacetate copolymer, orrubber. FIG. 3 illustrates the structure of the filler pad 21 thatincludes a heel portion 24 and a toe portion 23 which are made fromdifferent materials that differ in elasticity.

With reference to FIG. 4, a wear-resistant pad 70 can be attached to abottom surface of the base wall 221 of the thermoplastic skin 22 in themold 100 during the molding operation.

FIG. 5 is a block diagram showing consecutive steps of the secondpreferred embodiment of the method of this invention. With reference toFIG. 6, unlike the method of the previous embodiment, a positioningblock 111 is placed in the inner space 223 in the thermoplastic skin 22during the molding operation, and is removed from the mold 100 after themolding operation for insertion of the filler pad 21 through the bottomopening 14 into the inner space 223. The insole 13 is subsequently laidon an upper surface of the filler pad 21 and is connected to the bottomperipheral edge 12 of the upper 10 after the molding operation accordingto the method of this embodiment.

FIGS. 7 and 8 illustrate the structure of the thermoplastic skin 22 thatfurther includes a plurality of reinforcing ribs 224 formed on andprojecting from the base wall 221 into the inner space 223. The fillerpad 21 is formed with a plurality of grooves 211 for fittingly receivingthe reinforcing ribs 224 so as to enhance the strength of the outsole20.

FIG. 9 illustrates the third preferred embodiment of the method of thisinvention. Unlike the second preferred embodiment, the bottom peripheraledge 12 of the upper 10 extends to the base wall 221 of thethermoplastic skin 22, and the positioning block 111 is laid on thebottom peripheral edge 12 of the upper 10 and the base wall 221 of thethermoplastic skin 22. Similar to the previous embodiment, awear-resistant pad can be attached to the bottom surface of the basewall 221 of the thermoplastic skin 22.

Since the outsole 20 of the article of footwear is divided into thethermoplastic skin 22 and the filler pad 21, and since the thermoplasticskin 22 is relatively thin as compared to the filler pad 21 and is theonly one that is required to be preheated prior to the moldingoperation, the manufacturing time of the article of footwear can bereduced as compared to the aforementioned conventional method of theprior art. In addition, the filler pad 21 made from plastic waste isadvantageous and offers much benefit to the reduction of plastic waste.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretations andequivalent arrangements.

1. A method for making an article of footwear, comprising the steps of:preparing an upper that has a bottom peripheral edge; preparing athermoplastic skin that has a base wall and a peripheral wall whichextends from a periphery of said base wall in a transverse directionrelative to said base wall and which confines an inner space therein,said peripheral wall having a shape that conforms to that of said bottomperipheral edge of said upper; preparing a filler pad that has a shapeconforming to that of said base wall; mounting said upper on a last;preheating said thermoplastic skin to a softened state; and thermalmolding said softened thermoplastic skin together with an assembly ofsaid filler pad and said upper in a mold in such a manner that saidperipheral wall of said thermoplastic skin is patterned and is bonded tosaid bottom peripheral edge of said upper and that said filler pad isfittingly received in said inner space and is bonded to said base walland said peripheral wall of said thermoplastic skin.
 2. The method ofclaim 1, wherein said thermoplastic skin is made from ethylenevinylacetate copolymer.
 3. The method of claim 1, wherein saidthermoplastic skin is made from thermoplastic polyurethane.
 4. Themethod of claim 1, wherein said filler pad is made from plastic waste.5. The method of claim 1, further comprising attaching a wear-resistantpad to a bottom surface of said base wall in said mold during themolding operation.
 6. The method of claim 1, further comprising bindingan insole to said bottom peripheral edge of said upper prior to themolding operation.
 7. A method for making an article of footwear,comprising the steps of: preparing an upper that has a bottom peripheraledge which confines a bottom opening; preparing a thermoplastic skinthat has a base wall and a peripheral wall which extends from aperiphery of said base wall in a transverse direction relative to saidbase wall and which confines an inner space therein, said peripheralwall having a shape that conforms to that of said bottom peripheral edgeof said upper; preparing a filler pad that has a shape conforming tothat of said base wall; mounting said upper on a last; preheating saidthermoplastic skin to a softened state; thermal molding said softenedthermoplastic skin together with said upper in a mold in such a mannerthat said peripheral wall of said thermoplastic skin is patterned and isbonded to said bottom peripheral edge of said upper; cooling said moldand removing an assembly of said upper and said skin from said mold; andinserting fittingly said filler pad in said inner space through saidbottom opening in said upper.
 8. The method of claim 7, wherein saidthermoplastic skin is made from ethylene vinylacetate copolymer.
 9. Themethod of claim 7, wherein said thermoplastic skin is made fromthermoplastic polyurethane.
 10. The method of claim 7, wherein saidfiller pad is made from plastic waste.
 11. The method of claim 7,further comprising laying an insole on an upper surface of said fillerpad, and connecting said insole to said bottom peripheral edge of saidupper after the molding operation.